Glitches

Unlimited money
At the Smoldering Corpse Bar there is a woman disguising as a dustman, her name is Mochai. Talk to her and find out she is not of the Dustman, then ask for money to keep her secret a secret, you can do this as much as you like and you'll get 50 gold each time.

Unlimited experience with Hamrys
After retrieving the tomb plans down at the Lower Ward, go see Hamrys and tell him you have found the plans, then leave and talk to Hamrys again and do the same thing. You get 2000 exp each time you do this.

Unlimited experience with Karina
After joining Corvus with Karina at the Lower Ward's market, go see Karina again and talk to her for 500 exp, then leave and talk to her again and again for as long as you want. You get 500 exp each time.

Unlimited experience with Lenny
After gaining Lenny's trust down at the Lower Ward you can ask him to train you as a thief for 2500 exp, every time you get him to train you after this gets you another 2500 exp.

Unlimited experience with the sensory stones
In the Sensate Emporium (the private sensory stones), keep going to Ravel's stone and nodding until you have to speak, Then end the experience. You get 6000 exp every time.

The Nordom/Evil Wizard Bug
In the Modron Maze, set the difficulty to hard, find Nordom, find the Evil Wizard and get him to say he desintegrated the previous creative director, kill the wizard and talk to Nordom afterwards. Ask him how he came to Rubikon, then about the field test, and then about the previous director, he will now know the previous director was murdered by the Evil Wizard, tell him you are the new director for 36000 exp and an upgrade to Nordom: +1 INT & +1 DEX. Create a new maze in the hard difficulty and the Wizard will revive, find his room again and do the same as before. You can redo this upgrade to Nordom every time you visit the Evil Wizard and get him to confess the former director's murder.

Unlimited experience with Trias
After getting the Celestial Fire down at the Curst prison go speak to Trias, he'll ask you to free him with the Celestial Fire, leave and talk to him again; then select the dialogue options in this order: 1, 2, 1, 1, 2, 1. You should gain 306250 exp. Talk to him again and select dialogue option 2 "Ah well, farewell". Then, talk to him again and repeat the first sequence (1, 2, 1, 1, 2, 1). Each time you complete the sequence, you will get the 306250 exp.

Ancient Scroll Bug
When you get the Ancient Scroll from the Carceri Warehouse (x=396, y=286) put it in Ignus, or Dak'kon's inventory. It'll be red, but you can still use it. You can make all the wishes you want, because it'll never be consumed while in any other mage's inventory. You still need to be a level 12 mage to use it though.

Unilimited experience with Ebb (contributed by Radoslaw)
I haven't gotten around to test this yet, but according to Radoslaw, here's how it goes: In Carceri, when you enter the warehouse where the Wish scroll is hidden, there is Ebb Creakkness inside, and if you talk to him he gives 300,000 exp (as I remember); then leave the warehouse; enter it again, and as soon as you appear inside, IMMEDIATELY press space bar to pause the game, and you will see Ebb still there!!! talk to him for another 300,000 exp. and you can do this forever.

Mage Spells as a Fighter (or Thief) (contributed by Matt x)
Another glitch I am yet to test. Here's how it goes: Train as a mage and memorize some spells. Change your class to fighter or thief. Select a mage in your party (Ignus or Dak'kon). Left click to bring up the floating menu. Click the select all characters button. Click the cast mage spell button. You can now cast any mage spells you've learned and memorized as a mage. They'll be re-memorized if you rest just like if you're a mage. You can't change what spells you have, though, unless you change your class back to mage.
This hasn't been fixed by the 1.1 patch or Platter's 1.37 patch.

If you find any more exploitable glitches I'm missing be sure to tell me about it.